1. Field of the Invention
The present invention relates to a mobile communication device and a method for scaling data up/down on a touch screen, and in particular to a mobile communication device having a touch screen for displaying and entering data.
2. Description of the Related Art
Unlike a desktop personal computer, a mobile communication device needs to downsize its main body for increasing portability. Accordingly, the mobile communication device needs to keep a balance between conflicting requirements for downsizing a key input system and for assuring certain operability. Thus, various technologies have been developed for increasing operability of key input operations of such kind of mobile communication device.
The above mobile communication device, however, has a key configuration for which neither a size of a user's hand, a position where the mobile communication device is held, nor a range in which the user can move his or her fingers are considered. The mobile communication device is so configured that every user operates the mobile communication device in accordance with a unique key configuration. Every user consequently has to operate the mobile communication device in a way adapted for the mobile communication device. Thus, there is a problem that some users feel the mobile communication device hard to be operated in some cases.
In order to address the above problem, a mobile communication device having a touch panel is disclosed in Japanese Patent Publication of Unexamined Applications (Kokai), No. 2008-113148 The mobile communication device of JP 2008-113148 is configured to display a group of operation keys and to be operated through a touch panel. The mobile communication device of JP 2008-113148 is so configured that a layout of the group of operation keys displayed on the touch panel can be set according to an individual user. The mobile communication device of JP 2008-113148 is configured to judge a position and an area where the group of operation keys is displayed on the basis of a user's operation of drawing a trace on the touch panel.
A mobile communication device having a touch screen for both displaying and entering data needs to display lots of data so as to be easily viewed by a user. Meanwhile, the mobile communication device needs to scale up and display respective items of the data so as to be easily operated by the user with his or her fingers.
Thus, a mobile communication device having a touch screen needs to be so configured that a user can easily change a method for displaying data to be displayed. Moreover, the mobile communication device needs to be easily operated by the user so as to scale displayed data up/down. In a case where the user wants to operate the mobile communication device one-handed, the mobile communication device needs to be so configured that the user can direct the mobile communication device to scale displayed data up/down by using only one of his or her fingers.